LONDON — George Osborne, the former Chancellor of the Exchequer, said Britain's economy has "fallen off a cliff" since leaving the European Union and called for rejoining the EU customs union to reverse trade damage.

Osborne, who chairs the British Museum, made the comments in an interview with The Independent's editor-in-chief Geordie Greig. He campaigned against Brexit alongside then-Prime Minister David Cameron during the 2016 referendum.

"Brexit has been a mess. Britain has basically gone off a cliff," Osborne told Greig. "It has had a huge impact on the British economy" and the country is "clearly poorer than it would otherwise be."

He rejected the notion that the damage is permanent. "A bit like the Bayeux Tapestry isn't the end of the story, Brexit's not the end of the story," he said, referencing his role in bringing the tapestry to London for its first exhibition. Osborne said the UK needs broader discussion with European neighbors on immigration, the economy and regulation of new technologies.

While acknowledging that full EU membership would be difficult to achieve soon, Osborne proposed rejoining the customs union as "a relatively easy short-term remedy." He said it "was never part of the Brexit debate" and that "no one knew we were leaving it."

Osborne dismissed the original Brexit argument that leaving the customs union was necessary to strike major trade deals with the United States, calling those prospects "pretty fanciful now."

Osborne served as Conservative chancellor from 2010 to 2015 under the Conservative-Liberal Democrat coalition. He defended those years as a period of stability, contrasting them with the political turbulence that followed.

He criticized Conservative leader Kemi Badenoch's refusal to form an election pact with Nigel Farage, saying she would reverse course if it became necessary to regain power. He described her strategy as a "futile attempt to out-Reform Reform with right-wing policies."

Osborne praised new Labour Prime Minister Andy Burnham for his energy, though he noted Burnham has since recommitted to Labour's manifesto pledges not to rejoin the EU, single market or customs union.